Investigation and Control of a Diarrhea Outbreak in a Long Term Care Facility: A Tale of Two Causes

        Marian S. Rodgers, RN, MPH, CIC, Infection Control Practitioner, Patricia Lye, BA, MT, CIC, Infection Control Practitioner, Stephen M. Kralovic, MD, MPH, Hospital Epidemiologist, Donna Oblack, PhS, DABMM, Director, Marleen Burns, RN, MSN, ARNP, Chief Nurse, Suzanne Dinkelaker, RN, MSN, ARNP, Nurse Practitioner, The Cincinnati Veterans Adminstration Medical Center, Cincinnati, OH.
        Issue: A cluster of individuals with diarrhea in the nursing home (NH) were identified. The cluster included both patients and staff members. The community was at this time experiencing widespread gastrointestinal illness consistent with norovirus infection. Further investigation found additional cases in the inpatient domiciliary unit located in the same building.
        Project: Evaluation for etiologies included testing for Salmonella, Shigella, Camplylobacter, Yersinia, E.coli 0157, Clostridium difficile, Cryptosporidium, Giardia, and norovirus. The NH was closed to new admissions for the duration of the outbreak and the facility Christmas dinner was cancelled. Housekeeping implemented use of a 1:10 chlorine bleach solution for environmental cleaning. The NH instituted gowning and gloving for all patient contacts. Hand hygiene practices were reinforced. Symptomatic patients were not allowed to share space with well patients. No food from a patient tray could be stored for later use in a common refrigerator. All foods brought in by families and visitors were banned. Patients and employees were considered infectious until 48 hours after the cessation of symptoms. Information collected on all cases included date of onset of symptoms, symptoms, duration of illness, and culture results.
        Results: The cohort included all patients and staff at the NH facility with onset of diarrhea between 12/5/2006 and 12/25/2005. This included 19 long term care patients (attack rate [AR]: 31.7%), 3 long term care staff, 13 domiciliary patients (27.1% AR), and 8 domiciliary staff. Attack rates were not calculated for staff because information could not be ascertained for many. No staff members in housekeeping or in food service were symptomatic during this time. No stool specimens were received from the domiciliary; 13 were received from the NH. Of these, 5 long term care patients were positive for C.difficile and 5 were positive for norovirus (one had both). No staff specimens were sent for norovirus testing. Review of food histories and community contacts excluded Dietary as possible source. Patients positive for norovirus described prior contacts with ill visitors or family members.
        Lessons Learned:
        • 1.
          Implementation of control measures prevented transmission of both infections before laboratory results were available.
        • 2.
          Cooperation with outbreak testing recommendations may be poor among individuals able to care for themselves, such as employees or physically healthy patients.
        • 3.
          Control measures must consider the community as a potential source.
        • 4.
          Presence of a community viral outbreak does not exclude other possible causes such as C. difficile.
        • 5.
          Testing for all reasonable causes should be performed.